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Radiation
11.30.10
 
La vision de un artista acerca de una escena en el espacio, con los astronautas y la nave espacial

"Distant Shores" is an artist’s concept of a scene in space. NASA artwork by Pat Rawlings/SAIC.
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What Would You Hear in a Weather Report From Mars?

What is today’s high temperature? Is the sky mostly cloudy? Is there a chance of rain? Most of us listen to weather reports to help us decide what to wear and how to plan our day. Is lots of sun in the forecast? Don’t forget to wear sunscreen. Too much exposure to ultraviolet rays from the sun can lead to sunburn. We’re lucky here on Earth. Earth’s atmosphere contains a layer of ozone that prevents most of the ultraviolet rays from reaching us.

Living in space will be more dangerous. With no ozone protection, we’ll need to find new ways to protect ourselves from ultraviolet rays. And ultraviolet rays won’t be our biggest worry. Astronauts who live and work in space are exposed not only to ultraviolet rays but also to space radiation.

What do scientists know about space radiation? It is made mostly of energetic particles that can enter a person’s body. These particles can penetrate many objects, even if with extra shielding for protection. They can cause cancer, heart problems and cataracts. Space radiation can break down tissue in the human nervous system and even damage DNA inside the cells.

Erupcion solar roja y anaranjada

The largest solar flare ever recorded occurred on April 2, 2001, as observed by the Solar and Heliospheric Observatory, or SOHO, satellite. Image Credit: NASA
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Solar storms are one source of space radiation. Their biggest effect here on Earth is an increase in Earth’s aurora (northern and southern lights). Though an aurora creates beautiful bursts of color and light, solar storms can damage satellites, power grids and communications.

Solar storm effect can damage things on Earth. On March 6, 1989, a solar storm affected a power grid in Quebec, Canada, causing 6 million people to lose power for over nine hours. In May 1998, a solar storm disabled one satellite that caused automated teller machines, credit card-handling machines, and 80 percent of all pagers in the United States to stop working.

Within the Earth’s magnetosphere, Earth's magnetic field is very powerful and protects Earth from space radiation. Mars does not have the same kind of magnetic field as Earth. While on Mars and while traveling to and from Mars, astronauts will be exposed to space radiation.

Finding out more about space weather is important to NASA. In 2001, NASA placed a special space traveler on the International Space Station. The traveler, nicknamed “Fred,” was a model of the upper human body. Covered with artificial skin, this 43-kilogram- (95-pound-), 0.9-meter- (3-foot-) high mock-up contained real bones and plastic organs that closely matched the density of human tissue. Fred spent four months on the space station to measure how much radiation the human body absorbs.

El torso fantasma en el laboratorio Destiny de la estacion espacial

The Phantom Torso, also known as "Fred," is an anatomical model of a human torso and head. Fred contains hundreds of radiation-monitoring devices. Image Credit: NASA
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Results showed an increase in radiation entering the body, but scientists did not find as much as they expected. The levels were about 20 percent less than predicted.

While traveling on the space station, Fred still was protected by Earth's magnetosphere. Traveling farther into space and beyond Earth's protective magnetic fields will be more dangerous.

Weather reports from Mars must give us more information than what to wear or whether we’ll need an umbrella. Preparing for space weather will be much more difficult than preparing for Earth's.




 
 

Original Article: http://education.jsc.nasa.gov/explorers/sp/p11.html